The invention relates to doors, especially swinging-type doors which are hinged to the door frame of an opening through which people pass. More particularly, the invention relates to a mechanism or device for maintaining a predetermined fire rating for such swinging-type doors.
Fire rating is an important safety factor in the protection of people within a structure, whether it be an office building, hospital, or nursing home for the sick or elderly. Fire ratings vary with the thickness of a door, or the material composition of the door. The spacing around the door between an adjacent door or door jamb of a door frame is also an important factor in providing and maintaining a predetermined, desired fire rating. The invention is concerned with such a factor.
Briefly stated, the invention is in a device which is mountable on the so-called lock edge or side of a swinging-type door for adjusting the spacing between the lock side of the door and an adjacent door or door frame to maintain the spacing necessary for the desired fire rating of the door.